GB641746A - A starting arrangement for electric motors - Google Patents

Abstract

641,746. Controllers; centrifugal switches. MORAVIAN ELECTRICAL ENGINEERING WORKS, and HAK, J. Jan. 7, 1948, No. 520. Convention date, Jan. 8, 1947. '[Classes 38(iii) and 38(v)] In an arrangement for starting electric motors a number of switching-operations are performed, each at a different speed, by a centrifugal device which is urged into its initial position by a single restoring- force, for example that of a spring, and which is so arranged that in each switching-position the effective weight of the centrifugal device is reduced in order to obtain a stepwise operation. A motordriven disc a carries levers p 1 , p 2 , p 3 , mounting weights Q 1' Q 2' Q 3 , the whole assembly, when at rest, being pressed against abutment bo by spring p. As the motor-speed increases, weights Q 1 , Q 2' Q 3 , respectively engage stops b 1 , b 2 , b 3 , in turn to close contacts k 1 , k 2 , k 3 , in sequence. In a modification, Fig. 2, (not shown), one lever is pivoted to the disc, and each succeeding lever is carried by that preceeding it. In a further modification, Fig. 3, (not shown), two outer levers and a central lever are pivoted to the disc, the latter levers forming a contact-blade and having a bolt co-operating with slots in the outer levers. A number of systems of levers may be carried on the same disc.